1. Field of the Invention
The present invention relates to a wire electric discharge machine, and more particularly, to a wire electric discharge machine including a mechanism for collecting a cutoff piece (machined chip or machined product) that is produced by wire-electric discharge machining.
2. Description of Related Art
In machining a workpiece by use of a wire electric discharge machine, machined chips are usually produced as a cutoff piece. Machined chips produced by the wire electric discharge machining are different in form from those produced by other cutting machines. Depending on cases, a cutoff piece is utilized as machined product. Specifically, as depicted in FIG. 1, a lumped portion which is large in size is separated as a cutoff piece 2 from a workpiece 1. The lumped portion constitutes most part of machined chips or constitutes a machined product.
Such a cutoff piece falls into a machining tank. Since a lower arm, lower guide, etc. are disposed in the machining tank, the cutoff piece will likely to interfere with the lower arm, lower guide, etc., if it is left fallen in the tank. To obviate this, machined chips (or a machined product) are removed or collected manually by an operator immediately after being cut off from a workpiece. Also, there has been proposed a method for automatically collecting machined chips or machined products (see, JP2002-263958A), as a part of a robot-based system for automatically loading/unloading workpieces that has been developed to meet the demand of automated wire electric discharge machines.